The invention concerning an image forming device for forming an image such as a character or a photograph on a data recording surface or a label surface of a recording type optical disk that can record the data of a CD-R or a DVD-R and an optical disk suitable therefor has been hitherto proposed (for instance, see Patent Documents 1 and 2). This technique applies a phenomenon that colors are different between a part on which data is recorded by irradiating the data recording layer (a coloring matter layer) of the optical disk with a laser beam and a part on which the data is not recorded. This technique is used so that the image can be formed on the data recording surface of the optical disk or the label surface of the optical disk on which the coloring matter layer is formed on the label surface side of the optical disk.
However, since the optical disk is formed with a smooth and transparent base board, a problem arises that the visibility of the image formed on the optical disk is deteriorated due to unnecessary reflected light. When a track groove is formed on the data recording surface or the label surface, a rainbow-color appears on the surface due to the interference of light and a plurality of radial lines appear to deteriorate the visibility of the image. Further, in the case that the track groove is not formed on the label surface, a face or a background is reflected on the label surface as like a mirror, so that the visibility of the image is also deteriorated.
Thus, the invention concerning an optical disk with a reflection preventing layer having a micro irregular pattern formed on a disk board of an optical disk has been hitherto disclosed (for instance, see Patent Document 3). Further, the invention concerning a resin component that can efficiently form a micro irregular pattern on the disk board of an optical disk is disclosed (for instance, see Patent Documents 4 and 5). Further, the invention concerning an optical disk is disclosed in which the surface of an optical disk board is coated with a reflection preventing film (for instance, see Patent Document 6).    Patent Document 1: JP-A-2002-203321    Patent Document 2: JP-A-2004-039027    Patent Document 3: JP-A-2004-022157    Patent Document 4: JP-A-2005-092099    Patent Document 5: JP-A-2002-097371    Patent Document 6: JP-A-2001-143327